It is known that among geriatric patients pertrochanteric fractures are the most frequent in connection with those of the region of the neck of the bone. In fact, the advanced age and the pathologies which are encountered in these patients make necessary a timely stabilization of skeletal injuries in order to reduce to a minimum the bed confinement and the rehabilitation times by means of interventions which are less sanguinary and invasive as possible. In fact, it is necessary to avoid the complications brought about by the so-called immobilization syndrome, which may be lethal for patients in delicate metabolical compensation; and it is necessary to reduce to a minimum blood losses related to surgical intervention.
At the same time, the syntheses means utilized must be stable in order to allow the patient to very timely assume a seated position and, two or three days following the intervention, to reassume an erect posture with progressive weight.
A known technique for the consolidation of intertrochanteric, pertrochanteric, and subtrochanteric fractures of the femur involves the use of tubular intramedullary cavity nails with a proximal portion bent by some degrees in a medial-lateral plane with respect to a smaller diameter diaphysis portion in order to adapt to the physiological curvature of the femur. Sometimes, the curvature is present in two mutually orthogonal planes in order to favor further adaptation to the medullary cavity of the bone.
The known tubular nails are generally fixed by means of two diaphysis nails in order to block the rotation of the nail and one or two cephalic screws for compressing the spongy tissue in the focus fracture.
A first drawback of known intramedullary cavity nails of the above-described type resides in the fact that they have both a proximal part and a distal part of relatively elevated diameter, generally greater than 10-mm, and therefore their installation requires complex drilling of the bone for the entire length of the nail and can provoke internal stresses of the bone.
Moreover, the diaphysis screws are rather close to the distal end of the nail and can provoke stress concentrations and rupture of the femur at the base of the nail.
Finally, the cephalic screws are normally mutually parallel and therefore the head can be subject to slipping, with consequent loss of stability of the fracture.